Brake



Feb; 24, 193.1. A; N, cALKlNs 1,793,774

BRAKE Filed Feb. 4. 192e sheets-sheet 1 v( mi@ Feb. 24, 1931. A N, mms1,793,774

BRAKE Filed Feb. 4, 1928 2 Sheets-1511961. 2

Patented Feb. 24, 1931 unirse sraras PATENT OFFICE D-DISON N. CALKINS, FQINGY, ILLINOIS, ASSIGNOR T0 ELECTRIC WHEEL COM- i PANY, OF QUINCY,`ILLINGIS, A CORPORATION OF ILLINOIS BRAKE Application filed February/1,192B. Serial No. 251,801.

" z commensurate with the loads usually carried by crawler typevehicles, the brake must be applied to the crawler units which have arelatively largearea` in engagement with the ground, and it is theprimary object of the present invention to provide such a brake which isuniformly operative in any of the i positions of the crawler unit whichmay be caused by surface irregularities over which the vehicle maytravel. C

Another object is to provide a brake for the beltsupporting wheel ofsuch a vehicle which is'operable by a force acting longitudinallylof theaxle which supports the crawler unit.

no `A further object istoprovide a braking dervice `for a crawlerunithaving a separate wheel supporting each side of the track, a brake beingprovided for each of a pair of wheels and means for simultaneouslyoperat- A25 ing the two brakes in such a manner as to avoid unequalstresses upon the two wheels.

@ther objects ,and advantages will become 'apparent romtheiiollowingdescription and the accompanyingdrawings,in which Figure 1 is a planview vof a crawler type vehicle embodying the preferred form of thepresent invention. f

` 'Fig.2 is a fragment-al elevational view of oneof the crawler vunitsas viewed from the l 35 line 22 of Fig. 1, partojf the adjacent wheel jbeing broken away to disclosethe interior of A the brake drum. y

Fig. `3 is afiragmental elevational `view of the axle and thebrakeoperating partsfasso- 3 '45 operatingmeans.

`lhile the invention is susceptible of various modificationsandalternative constructions, I have shownin the drawings and willVherein describe in detail the preferred embodiment,

50 i `but it is to be understood that I do not thereby intend to limitthe invention to the specic form disclosed but intend to cover allmodifications and alternative constructions falling within the spiritand scope of the invention as expressed in the appended claims.

In the drawings the invention is shown as applied to a trailer vehicleequipped with crawler units.` The vehicle illustrated has a main framecomposed of side rails 5 and end members 6. An axle 7 is stationarilysecured beneath the frame and projects beyond the side rails 5 toreceive suitable crawler units designated generally as 10 (Fig. 1) whichare pivotally mounted on the aXleso that the position of crawler unitsmay be varied by the contour of the ground without transmitting theentire movement to the frame.

The crawler` units 10 are similar in character, each comprising, ingeneral, a frame or beam 11, two pairs oi wheels 12 and 13 mounted atopposite ends of the beam, and an endless belt 1e mounted on and guidedby the wheels, the beam 11 being' pivotally mounted on the axle 7, allin a well known manner.

Braking` means is provided for stopping or controlling the rotation ofthe pair of wheels 13 of each crawler unit 10. As herein illustrated, aninwardly extending brake drum 15 is formed on the inner side of each ofsaid wheels 13 and a pair of expansible brake shoes 16 are positionedwithin each brake drum. A closure plate 17 is mounted on each side ofthe beam 11 so as to completely close the open end ot' the brake drum 15and thus protect the braking elements from dust and dirt. Alined stubshafts 2O are rotatably mounted in bosses` 21 formed in the closureplates 17 and cam blocks 22 are secured thereon between the flanged ends23 of the brake shoes 16 so that the brake shoes may be expanded byrotation of the shafts 20. y p

` The means provided for applying the brakes is preferably of suchacharacter that it is unaffectedby the rotative movement of the crawler4units relative to the frame and hence operable uniformly to apply, thebrake regardless oi the position of the units.

In the presentinstance this means includes 4two relatively ,rotatablemembers 25 and 26 A ie mounted about the axles 7 and associated in sucha manner that movement of one of the members longitudinally Vof the axle'l' will be transmitted to the other member. The meinber 25 is hereinshown as a sleeve (Figs. 2, 3 and 4) non-rotatably .mounted Aon the axle7 adjacent the inner side of the crawler unit 10 and arranged to slidelongitudinallyof the axle away from the unit (to the left in Fig. 3).The'member 26 is in the form of a collar which loosely surrounds thesleeve 25 and isV Varranged to be moved with the sleeve 25longitudinally of the axle away from the crawler unit 10 by a flange 27formed on the sleeve 25.

The operative connection betweenV the .braking means andthe collar 26 issuch as to transmit and change the direction of -the forces so that thebrakema-y be applied by moving the collar 26 along the axle away fromthe crawler unit. YThis means preferably in- Y cludes, in each instance,a bell crank 30 which serves to change the direction of the forces. Thebell crank 30 Vastherein shown comprises a sleeve 31 rotatably mountedon a vertical .stubshaft 32 which is secured in the beam 11,

`an arm 33 extending from the sleeve near the centerthereof and two arms34 extending one from the ltop ofthel sleeve and one from the bottom atanl angle tothe arm 33.. The arms 34ers connected to the top and bottomlrespectively of thecollar 26 by means of links 35, the endsofthe linksbeing Lpivotally secured to the arms 34 and the collar 26.V The arm 33is connected to the braking means iny a manner which will now bedescribed.

As shown mostclearly 1n Fig. 5, a lever isY secured to the inner end ofeach of the shafts 20 .so as to extend downwardly from the shafts. Anaperture 41 is formed inthe lowerend of each lever so as to receive theends of an equalizing bar 42 which extends between rthe two levers. Anadjustable link 43 ispivotally secured at its opposite ends to the arm33 ofthe bell crank and the middle ofthe i bar 42. Thus an equalizingconnection is provided which servesto equally 4retard'the two wheelssoas to avoid undue strainupon either V-of the wheels.

in order that the collar 26 maybecaused to rockahout the ,axle `7. withthe-crawler *unit 10, a pair of lplates'.451are-securedito the topandbottom respectively of the beam 11 so as ,to extendinwardlytherefrom,v and guide slots 46 lare formed therein to receivethe ends of ,bolts .47,.which are securedto thecollar 26 and'which ralsoserve asfpivots for the links 35'.

Means .is lpreferably provided .for simultaneously lmoving vthe sleeves25V on the two Asides ofthe Vvehicle so astoapply the brakes to-bothcrawler units V10. As herein shown thisY means Vcomprises a longitudinalshaft 48 rotatablymountedat itsopposite ends on the end memberfofthe'frameand on the axle `v7.

Y l -Eorthelpu1poseof rotating the shaft 48, a Shaft having crankhandles' 50 and has a short lever 55 secured to its other Y end. Thelevers 53 and 55 are connected to the sleeve` 25 by means of links 56 sothat when the shaft 48 is rotated so as to shorten the chains 52, thesleeves 25 will be drawn toward the middle of the axle so as to vapplythe brakes. Y

Means is preferably provided to restore the parts to their normal brakereleased position when the chains 52 are unwound from the shaft. spring60 is connected to the free ends of the brake shoes 16 so as to opposethe expansion thereof and thus when the cam 22 is returned to itsinoperative position, the brake shoes 16 will be drawn together and outof contact with thedrum 15. For the purpose of returning the cam 22, thebell crank 30, the collar 26andsleeve 25 to normal brake releasingposition after the chains 52 have been loosened, a spring 61 (Fig. 4) isconnected to the beam 11l andthe arm 33 ofthe bell crank 30 so that thespring will oppose the movement of these parts in'settingthe brake.

In the operation of the device braking force vis applied to both ofthecrawler units by means of the-handles 50 whichserve'to rotate the shaft48 extending longitudinally ofthe main frame. Rotation of the shaft 48serves through the medium of the flexible connection 52,Y the levers 53and-the links 56 to move the two members 25jlongitudinally of the axle 7inwardly toward the main frame. The

.movement of the members 25 Vis transmitted to the brakeoperatingconnections mounted on the crawler frames by means ofthe links35, one end of each linkbeing guidedbythe yslot inthe plate A45 for.movement along a delinite ypathinfxed relation to the crawler frames bythe bolt 47 whichL engages the member 25 so as to be moved by themember-25 and arranged to permit relativejretative fmovement of thecrawler unit and the axle. i

Y The other end of each link-35 vis connected to an arm of a bell crankmounted on thecr'aw- Y As herein shown a retractileV brake, the springs60 and 61 serve to return the various parts to their inoperativeposition.

From the foregoing description it will be apparent that the inventionprovides a brake y for crawler type vehicles which is uniformlyoperative to apply the brake irrespective of the position of the crawlerunits thereof. It will also be apparent that the invention provides abrake which will not subject the parts of the crawler unit to unequalstresses which would tend to distort or break such parts.

I claim as my invention:

. l. The combination with a crawler type vehicle having a main frame, anaxle, a side frame rotatably mounted on said axle, a pair ol. wheelsrotatably and eoaxially mounted on each end of said side frame, and anendless belt on said wheels; of means for applying braking force to onepair of said wheels comprising a pair of brake drums, one on each wheel,a pair of braking elements mounted on each side frame, one of saidelements ar-A ranged to engage each of said drums, a pair of levers, onearranged to operate each ot said braking elements to cause suchengagement, an equalizing bar connected at opposite ends to said levers,a member longitudinally movable with respect to said axle and arrangedto rock with said side frame, meanson the axle movable longitudinallythereof and arraneed to move said member therewith, and means connectingsaid member and said equalizing bar operable to transmit the motion ofsaid member to said bar to apply said brakes.

2. The combination with a crawler type vehicle having a main frame, anaxle secured thereto, a side trame pivotally supported on said axle,wheels rotatably mounted on said side frame, and an endl-ess belt onsaid wheels,

oli' braking means for said Vehicle comprising a brake drum on one ofsaid wheels, a braking element operable to engage said drum to controlthe rotation of said wheel, a member longitudinally movable with respectto said axle and arranged to rotate about said axle with said. sideframe, means on the axle movable longitudinally thereof and arranged toengage said member to move said member therewith, and means connectingsaid member' andV said braking element operable upon movement of saidmember to engage said braking element with said drum.

3. The combination with a crawler type vehicle having a main trame, anaxle, a side frame pivotally support-ed on said axle, wheels rotatablymounted on said side frame, and an endless belt on said wheels, oi abrake for said vehieleeomprising a brake drum on one of said wheels, abraking element operable to engage said drum to control the rota- Vtionof said wheel, a member mounted on said axle for longitudinal movementthereon and arranged to rotate about said axle with said side frame,means connecting said member and said braking element operable uponmovement of said member alongsaid axle to engage said braking` elementwith said drum, and means fixed on `said axle against rotation relativethereto butmovable longitudinally thereon to engage and move said memberirrespective et' its position on said axle.

Ll. llibrake device lona crawler type vehicle having a main vframe, anaxle, and a crawler unit mounted on said axle for rotation thereabout,said device 'comprising braking means on said crawler unit operable tocontrol operation of said unit, a member mounted on said axle 'for axialmovement thereon and rotatable about said axle with said crawler unit,means connecting said member and said braking means arranged to operatesaid braking means when said member is moved longitudinally ot' saidaxle, and a part mounted for longitudinal movement but against rotativemovement relative to said axle and arranged to engage said member in anyoli its positions to transmit longitudinal movement thereto.

5. il brake device for a crawler type vehicle having an axle and acrawler unit pivotally mounted thereon, said device comprising brakingmeans operable to control or stop the normal operation of said crawlerunit, operating means for said braking means including a part mountedfor rotation with said unit about said axle and longitudinally slidablealong said axle to operate said brake, a member slidably mounted on saidaxle to transmit longitudinal motion to said part, and means operable tomove said member along said axle whereby said brake may be operated.

6. A vehicle comprising, in combination, a main frame, crawler unitspivoted on and supporting said frame, each of said units including anendless belt and guide wheels therefor, braking means operable to applybraking force to one oi said wheels and having one Jfriction element ofsaid means mounted on said wheel, operating means for said braking meansmounted on said main frame and means operatively connecting saidoperating means to said braking means arranged whensaid operatingmeansis actu-` ated in a given amount to apply said brakmeans to the samedegree irrespective of the relative angular relation of said crawlerunit and said frame.

7. In a vehicle having a main frame, an`

axle, and a pair ot crawler units, one rockably secured on each end ofsaid axle, the

arranged to be unaffected by the rocking movement of said crawler unitsrelative to said frame.

8. A brake device for a crawler type vehicle having a main frame with anaxle and a crawler unit pivotally mounted thereon, said clevlceComprising braking means operable to control or stop the normaloperation of said crawler unit, and operating means 'for said brakingmeans including a Vmember mounted 'for rotation with saidv unit andsliclable on said unit longitudinally with respect to said axle tooperate said brake, a second member l mounted on said main frame forsliding movement longitudinally With respect to said axle, said membershaving a uniform operative engagement in vall angular positions ofV.said crawler unit relatively to said man1 f frame, and means on saidmain frame operable vto move said second member whereby to operate saidbrake.

In testimony whereof7 I have hereunto afi fixed my signature.

ADDISON N. CALKINS.

